Davfs2
Davfs2 allows you to access resources on a remote server like it would be a local disk, in this case nextcloud.
Install and configure davfs2
Install davfs2:
sudo apt-get install davfs2
Add yourself to davfs group:
sudo usermod -aG davfs2 <username>
Create a directory, and mount it:
mkdir ~/nextcloud sudo mount -t davfs https://files.newro.co/remote.php/dav/files/<username>/ ~/nextcloud
After the mount you will be prompted for your username and password from nextcloud.
Please unmount the nextcloud directory when finished, makes it harder to scan for big directories in case a VM has storage issues. Plus, you're leaving your nextcloud files exposed to others.
You can unmount the directory like this:
umount ~/nextcloud
Troubleshooting
If you get something like this when mounting /sbin/mount.davfs: warning: the server does not support locks then edit /etc/davfs2/davfs2.conf file and set use_locks 0